mon/OSDMonitor: Using crush_rulename rather than id when set/get crush_ruleset.



Like ceph osd crush ls/list/rm, they using rule name rather than id.

Signed-off-by: Ma Jianpeng <jianpeng.ma@intel.com>
This is assigning a rule ID as a ruleset ID, which will break under circumstances where there does not happen to be a ruleset with the same ID as the rule.